/*

 * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

# include <signal.h>        // needed first to avoid name collision for "std" with SC 5.0

// put OS-includes here

# include <sys/types.h>

# include <sys/mman.h>

# include <pthread.h>

# include <errno.h>

# include <dlfcn.h>

# include <stdio.h>

# include <unistd.h>

# include <sys/resource.h>

# include <thread.h>

# include <sys/stat.h>

# include <sys/time.h>

# include <sys/filio.h>

# include <sys/utsname.h>

# include <sys/systeminfo.h>

# include <sys/socket.h>

# include <sys/lwp.h>

# include <pwd.h>

# include <poll.h>

# include <sys/lwp.h>

# define _STRUCTURED_PROC 1  //  this gets us the new structured proc interfaces of 5.6 & later

# include <sys/procfs.h>     //  see comment in <sys/procfs.h>

#define MAX_PATH (2 * K)

// Minimum stack size for the VM.  It's easier to document a constant

// but it's different for x86 and sparc because the page sizes are different.

#ifdef _LP64

size_t os::Solaris::min_stack_allowed = 128*K;

#else

size_t os::Solaris::min_stack_allowed = 96*K;

#endif

int os::Solaris::max_register_window_saves_before_flushing() {

  // We should detect this at run time. For now, filling

  // in with a constant.

  return 8;

}

static void handle_unflushed_register_windows(gwindows_t *win) {

  int restore_count = win->wbcnt;

  int i;

  for(i=0; i<restore_count; i++) {

    address sp = ((address)win->spbuf[i]) + STACK_BIAS;

    address reg_win = (address)&win->wbuf[i];

    memcpy(sp,reg_win,sizeof(struct rwindow));

  }

}

char* os::non_memory_address_word() {

  // Must never look like an address returned by reserve_memory,

  // even in its subfields (as defined by the CPU immediate fields,

  // if the CPU splits constants across multiple instructions).

  // On SPARC, 0 != %hi(any real address), because there is no

  // allocation in the first 1Kb of the virtual address space.

  return (char*) 0;

}

// Validate a ucontext retrieved from walking a uc_link of a ucontext.

// There are issues with libthread giving out uc_links for different threads

// on the same uc_link chain and bad or circular links.

//

bool os::Solaris::valid_ucontext(Thread* thread, ucontext_t* valid, ucontext_t* suspect) {

  if (valid >= suspect ||

      valid->uc_stack.ss_flags != suspect->uc_stack.ss_flags ||

      valid->uc_stack.ss_sp    != suspect->uc_stack.ss_sp    ||

      valid->uc_stack.ss_size  != suspect->uc_stack.ss_size) {

    DEBUG_ONLY(tty->print_cr("valid_ucontext: failed test 1");)

    return false;

  }

  if (thread->is_Java_thread()) {

    if (!valid_stack_address(thread, (address)suspect)) {

      DEBUG_ONLY(tty->print_cr("valid_ucontext: uc_link not in thread stack");)

      return false;

    }

    address _sp   = (address)((intptr_t)suspect->uc_mcontext.gregs[REG_SP] + STACK_BIAS);

    if (!valid_stack_address(thread, _sp) ||

        !frame::is_valid_stack_pointer(((JavaThread*)thread)->base_of_stack_pointer(), (intptr_t*)_sp)) {

      DEBUG_ONLY(tty->print_cr("valid_ucontext: stackpointer not in thread stack");)

      return false;

    }

  }

  return true;

}

// We will only follow one level of uc_link since there are libthread

// issues with ucontext linking and it is better to be safe and just

// let caller retry later.

ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread,

  ucontext_t *uc) {

  ucontext_t *retuc = NULL;

  // Sometimes the topmost register windows are not properly flushed.

  // i.e., if the kernel would have needed to take a page fault

  if (uc != NULL && uc->uc_mcontext.gwins != NULL) {

    ::handle_unflushed_register_windows(uc->uc_mcontext.gwins);

  }

  if (uc != NULL) {

    if (uc->uc_link == NULL) {

      // cannot validate without uc_link so accept current ucontext

      retuc = uc;

    } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {

      // first ucontext is valid so try the next one

      uc = uc->uc_link;

      if (uc->uc_link == NULL) {

        // cannot validate without uc_link so accept current ucontext

        retuc = uc;

      } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {

        // the ucontext one level down is also valid so return it

        retuc = uc;

      }

    }

  }

  return retuc;

}

// Assumes ucontext is valid

ExtendedPC os::Solaris::ucontext_get_ExtendedPC(ucontext_t *uc) {

  address pc = (address)uc->uc_mcontext.gregs[REG_PC];

  // set npc to zero to avoid using it for safepoint, good for profiling only

  return ExtendedPC(pc);

}

// Assumes ucontext is valid

intptr_t* os::Solaris::ucontext_get_sp(ucontext_t *uc) {

  return (intptr_t*)((intptr_t)uc->uc_mcontext.gregs[REG_SP] + STACK_BIAS);

}

// Solaris X86 only

intptr_t* os::Solaris::ucontext_get_fp(ucontext_t *uc) {

  ShouldNotReachHere();

  return NULL;

}

// For Forte Analyzer AsyncGetCallTrace profiling support - thread

// is currently interrupted by SIGPROF.

//

// ret_fp parameter is only used by Solaris X86.

//

// The difference between this and os::fetch_frame_from_context() is that

// here we try to skip nested signal frames.

ExtendedPC os::Solaris::fetch_frame_from_ucontext(Thread* thread,

  ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {

  assert(thread != NULL, "just checking");

  assert(ret_sp != NULL, "just checking");

  assert(ret_fp == NULL, "just checking");

  ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc);

  return os::fetch_frame_from_context(luc, ret_sp, ret_fp);

}

// ret_fp parameter is only used by Solaris X86.

ExtendedPC os::fetch_frame_from_context(void* ucVoid,

                    intptr_t** ret_sp, intptr_t** ret_fp) {

  ExtendedPC  epc;

  ucontext_t *uc = (ucontext_t*)ucVoid;

  if (uc != NULL) {

    epc = os::Solaris::ucontext_get_ExtendedPC(uc);

    if (ret_sp) *ret_sp = os::Solaris::ucontext_get_sp(uc);

  } else {

    // construct empty ExtendedPC for return value checking

    epc = ExtendedPC(NULL);

    if (ret_sp) *ret_sp = (intptr_t *)NULL;

  }

  return epc;

}

frame os::fetch_frame_from_context(void* ucVoid) {

  intptr_t* sp;

  intptr_t* fp;

  ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);

  return frame(sp, frame::unpatchable, epc.pc());

}

frame os::get_sender_for_C_frame(frame* fr) {

  return frame(fr->sender_sp(), frame::unpatchable, fr->sender_pc());

}

frame os::current_frame() {

  intptr_t* sp = StubRoutines::Sparc::flush_callers_register_windows_func()();

  frame myframe(sp, frame::unpatchable,

                CAST_FROM_FN_PTR(address, os::current_frame));

  if (os::is_first_C_frame(&myframe)) {

    // stack is not walkable

    return frame(NULL, NULL, NULL);

  } else {

    return os::get_sender_for_C_frame(&myframe);

  }

}

void GetThreadPC_Callback::execute(OSThread::InterruptArguments *args) {

  Thread*     thread = args->thread();

  ucontext_t* uc     = args->ucontext();

  intptr_t* sp;

  assert(ProfileVM && thread->is_VM_thread(), "just checking");

  // Skip the mcontext corruption verification. If if occasionally

  // things get corrupt, it is ok for profiling - we will just get an unresolved

  // function name

  ExtendedPC new_addr((address)uc->uc_mcontext.gregs[REG_PC]);

  _addr = new_addr;

}

static int threadgetstate(thread_t tid, int *flags, lwpid_t *lwp, stack_t *ss, gregset_t rs, lwpstatus_t *lwpstatus) {

  char lwpstatusfile[PROCFILE_LENGTH];

  int lwpfd, err;

  if (err = os::Solaris::thr_getstate(tid, flags, lwp, ss, rs))

    return (err);

  if (*flags == TRS_LWPID) {

    sprintf(lwpstatusfile, "/proc/%d/lwp/%d/lwpstatus", getpid(),

            *lwp);

    if ((lwpfd = open(lwpstatusfile, O_RDONLY)) < 0) {

      perror("thr_mutator_status: open lwpstatus");

      return (EINVAL);

    }

    if (pread(lwpfd, lwpstatus, sizeof (lwpstatus_t), (off_t)0) !=

        sizeof (lwpstatus_t)) {

      perror("thr_mutator_status: read lwpstatus");

      (void) close(lwpfd);

      return (EINVAL);

    }

    (void) close(lwpfd);

  }

  return (0);

}

bool os::is_allocatable(size_t bytes) {

#ifdef _LP64

   return true;

#else

   return (bytes <= (size_t)3835*M);

#endif

}

extern "C" void Fetch32PFI () ;

extern "C" void Fetch32Resume () ;

extern "C" void FetchNPFI () ;

extern "C" void FetchNResume () ;

extern "C" int JVM_handle_solaris_signal(int signo, siginfo_t* siginfo, void* ucontext, int abort_if_unrecognized);

int JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrecognized) {

  ucontext_t* uc = (ucontext_t*) ucVoid;

  Thread* t = ThreadLocalStorage::get_thread_slow();

  SignalHandlerMark shm(t);

  if(sig == SIGPIPE || sig == SIGXFSZ) {

    if (os::Solaris::chained_handler(sig, info, ucVoid)) {

      return true;

    } else {

      if (PrintMiscellaneous && (WizardMode || Verbose)) {

        char buf[64];

        warning("Ignoring %s - see 4229104 or 6499219",

                os::exception_name(sig, buf, sizeof(buf)));

      }

      return true;

    }

  }

  JavaThread* thread = NULL;

  VMThread* vmthread = NULL;

  if (os::Solaris::signal_handlers_are_installed) {

    if (t != NULL ){

      if(t->is_Java_thread()) {

        thread = (JavaThread*)t;

      }

      else if(t->is_VM_thread()){

        vmthread = (VMThread *)t;

      }

    }

  }

  guarantee(sig != os::Solaris::SIGinterrupt(), "Can not chain VM interrupt signal, try -XX:+UseAltSigs");

  if (sig == os::Solaris::SIGasync()) {

    if (thread) {

      OSThread::InterruptArguments args(thread, uc);

      thread->osthread()->do_interrupt_callbacks_at_interrupt(&args);

      return true;

    } else if (vmthread) {

      OSThread::InterruptArguments args(vmthread, uc);

      vmthread->osthread()->do_interrupt_callbacks_at_interrupt(&args);

      return true;

    } else if (os::Solaris::chained_handler(sig, info, ucVoid)) {

      return true;

    } else {

      // If os::Solaris::SIGasync not chained, and this is a non-vm and

      // non-java thread

      return true;

    }

  }

  if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {

    // can't decode this kind of signal

    info = NULL;

  } else {

    assert(sig == info->si_signo, "bad siginfo");

  }

  // decide if this trap can be handled by a stub

  address stub = NULL;

  address pc          = NULL;

  address npc         = NULL;

  //%note os_trap_1

  if (info != NULL && uc != NULL && thread != NULL) {

    // factor me: getPCfromContext

    pc  = (address) uc->uc_mcontext.gregs[REG_PC];

    npc = (address) uc->uc_mcontext.gregs[REG_nPC];

    // SafeFetch() support

    // Implemented with either a fixed set of addresses such

    // as Fetch32*, or with Thread._OnTrap.

    if (uc->uc_mcontext.gregs[REG_PC] == intptr_t(Fetch32PFI)) {

      uc->uc_mcontext.gregs [REG_PC]  = intptr_t(Fetch32Resume) ;

      uc->uc_mcontext.gregs [REG_nPC] = intptr_t(Fetch32Resume) + 4 ;

      return true ;

    }

    if (uc->uc_mcontext.gregs[REG_PC] == intptr_t(FetchNPFI)) {

      uc->uc_mcontext.gregs [REG_PC]  = intptr_t(FetchNResume) ;

      uc->uc_mcontext.gregs [REG_nPC] = intptr_t(FetchNResume) + 4 ;

      return true ;

    }

    // Handle ALL stack overflow variations here

    if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) {

      address addr = (address) info->si_addr;

      if (thread->in_stack_yellow_zone(addr)) {

        thread->disable_stack_yellow_zone();

        // Sometimes the register windows are not properly flushed.

        if(uc->uc_mcontext.gwins != NULL) {

          ::handle_unflushed_register_windows(uc->uc_mcontext.gwins);

        }

        if (thread->thread_state() == _thread_in_Java) {

          // Throw a stack overflow exception.  Guard pages will be reenabled

          // while unwinding the stack.

          stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);

        } else {

          // Thread was in the vm or native code.  Return and try to finish.

          return true;

        }

      } else if (thread->in_stack_red_zone(addr)) {

        // Fatal red zone violation.  Disable the guard pages and fall through

        // to handle_unexpected_exception way down below.

        thread->disable_stack_red_zone();

        tty->print_raw_cr("An irrecoverable stack overflow has occurred.");

        // Sometimes the register windows are not properly flushed.

        if(uc->uc_mcontext.gwins != NULL) {

          ::handle_unflushed_register_windows(uc->uc_mcontext.gwins);

        }

      }

    }

    if (thread->thread_state() == _thread_in_vm) {

      if (sig == SIGBUS && info->si_code == BUS_OBJERR && thread->doing_unsafe_access()) {

        stub = StubRoutines::handler_for_unsafe_access();

      }

    }

    else if (thread->thread_state() == _thread_in_Java) {

      // Java thread running in Java code => find exception handler if any

      // a fault inside compiled code, the interpreter, or a stub

      // Support Safepoint Polling

      if ( sig == SIGSEGV && (address)info->si_addr == os::get_polling_page() ) {

        stub = SharedRuntime::get_poll_stub(pc);

      }

      // Not needed on x86 solaris because verify_oops doesn't generate

      // SEGV/BUS like sparc does.

      if ( (sig == SIGSEGV || sig == SIGBUS)

           && pc >= MacroAssembler::_verify_oop_implicit_branch[0]

           && pc <  MacroAssembler::_verify_oop_implicit_branch[1] ) {

        stub     =  MacroAssembler::_verify_oop_implicit_branch[2];

        warning("fixed up memory fault in +VerifyOops at address " INTPTR_FORMAT, info->si_addr);

      }

      // This is not factored because on x86 solaris the patching for

      // zombies does not generate a SEGV.

      else if (sig == SIGSEGV && nativeInstruction_at(pc)->is_zombie()) {

        // zombie method (ld [%g0],%o7 instruction)

        stub = SharedRuntime::get_handle_wrong_method_stub();

        // At the stub it needs to look like a call from the caller of this

        // method (not a call from the segv site).

        pc = (address)uc->uc_mcontext.gregs[REG_O7];

      }

      else if (sig == SIGBUS && info->si_code == BUS_OBJERR) {

        // BugId 4454115: A read from a MappedByteBuffer can fault

        // here if the underlying file has been truncated.

        // Do not crash the VM in such a case.

        CodeBlob* cb = CodeCache::find_blob_unsafe(pc);

        nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL;

        if (nm != NULL && nm->has_unsafe_access()) {

          stub = StubRoutines::handler_for_unsafe_access();

        }

      }

      else if (sig == SIGFPE && info->si_code == FPE_INTDIV) {

        // integer divide by zero

        stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);

      }

      else if (sig == SIGFPE && info->si_code == FPE_FLTDIV) {

        // floating-point divide by zero

        stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);

      }

#ifdef COMPILER2

      else if (sig == SIGILL && nativeInstruction_at(pc)->is_ic_miss_trap()) {

#ifdef ASSERT

  #ifdef TIERED

        CodeBlob* cb = CodeCache::find_blob_unsafe(pc);

        assert(cb->is_compiled_by_c2(), "Wrong compiler");

  #endif // TIERED

#endif // ASSERT

        // Inline cache missed and user trap "Tne G0+ST_RESERVED_FOR_USER_0+2" taken.

        stub = SharedRuntime::get_ic_miss_stub();

        // At the stub it needs to look like a call from the caller of this

        // method (not a call from the segv site).

        pc = (address)uc->uc_mcontext.gregs[REG_O7];

      }

#endif  // COMPILER2

      else if (sig == SIGSEGV && info->si_code > 0 && !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {

        // Determination of interpreter/vtable stub/compiled code null exception

        stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);

      }

    }

    // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in

    // and the heap gets shrunk before the field access.

    if ((sig == SIGSEGV) || (sig == SIGBUS)) {

      address addr = JNI_FastGetField::find_slowcase_pc(pc);

      if (addr != (address)-1) {

        stub = addr;

      }

    }

    // Check to see if we caught the safepoint code in the

    // process of write protecting the memory serialization page.